Engine cooling system



A. E. KOLBE E A ENGINE COOLING SYSTEM Oct. 20, 1959 2 Sheets-Sheet 1 Original Filed Oct. 4, 1954 INVENTORS @71 5! 6. Mai

TTRNEY Oct. 20, 1959 A. E. KOLBE ETA!- 2,909,162

, ENGINE COOLING SYSTEM Original Filed Oct. 4. 1954 2 Sheets-Sheet 2 United States Patent M ENGINE COOLING SYSTEM Adelbert E. Kolbe, Berkley, and Earl W. Rohrbacher,

Birmingham, Mich., assignors to General Motors Corporation, Detroit, Mich., a corporation of Delaware Original application October 4, 1954, Serial No. 460,205, now Patent No. 2,862,483, dated December 2, 1958. Divided and this application April 23, 1958, Serial No. 730,349

3 Claims. (Cl. 123-41.73)

This application is a division of US. Patent No. 2,862,483 in the names of Adelbert E. Kolbe and Earl W. Rohrbacher, filed October 4, 1954 and granted December 2, 1958. a

The invention relates to cooling systems for internal combustion engines and has particular relation to an improved cooling system especially applicable for V-type, 8-cylinder internal combustion engines for automotive and other uses.

It has been the practice heretofore to construct'cooling systems for internal combustion engines by providing cooling cavities in the heads and blocks of engines and then supplying cooling liquid to and exhausting cooling liquid from these cavities. To provide a good cooling system it has been the practice to make these cavities as large as possible within the space and cost limitations applicable, it having been assumed that the availability to be cooled would provide the best cooling system possible. However, it now appears that in these systems the cooling liquid supplied generally circulated between the cavity inlets and outlets by the shortest possible path or by the path offering the least restriction to the flow of cooling liquid. Since the cavities were large thecooling liquid had a tendency to stratify in other parts of the cavities and to circulate only by thermosyphon circulation caused by the adjacent heated partsof the engine or by entrainment in the stream of cooling liquid flowing between the inlet and the outlet for the cavities. Since the most highly heated parts of the engine Were usually not in the shortest path between the inlet and the outlet or the path where there was less restriction to the flow of: cooling liquid between the inlet and the outlet, the parts requiring the greatest cooling often were provided with the least efi'ective means for cooling. Also, the provision of large cooling cavities tended to enclose parts that did not require cooling. This caused the heat rejection to the cooling liquid to be excessive and required excessive and unnecessarily expensive heat radiating means for the engine.

It is proposed to limit the size of the cooling liquid cavities in an internal combustion engine and to provide means for directing the circulation of cooling liquid Within the cavities so that substantially all of the cooling liquid in the cavities will be compelled to follow definite circulation paths within the cavities and over the parts of the engine that especially require cooling by the cooling liquid supplied to the engine. The reduction in the size of the cooling cavities particularly in the heads of the engine tends to exclude from the cavities various heated parts of the engine that do not require cooling. Since this decreases the amount of heat that must be absorbed by the cooling liquid circulated throughout the engine, it is possible to employ a small much less expensive radiator for the engine. In these cooling cavities of reduced size it is proposed to provide means for creating a definite and continuous circulation throughout the cooling cavities of the engine so that the cooling liquid of large quantities of cooling liquid adjacent .the parts 2,909,162 Patented ,Oct. 20, 1959 will be positively circulated over all the heated parts of the engine that require cooling. Hence the stratification of liquid in various parts of the cooling cavities where cooling is required will be greatly reduced if not entirely eliminated. In parts. of the engine where space limita tions might require the construction of narrow passages and in parts through which the circulation of cooling liquid would be difiicult it is proposed to,employ cooling by conductivity through the metallic parts of the engine to places where better circulation of cooling liquid can be obtained. This also reduces the rejection of heatto the cooling liquid of the engine and therefore decreases the size of the radiator due to the fact that these heat conducting parts also radiateheat to various objects adja cent the engine and are cooled by the air surrounding the engine so that the amount of heat that must be conducted to the cooling liquid is materially reduced. It is also proposed to provide a pump for the engine that will efiectively increase the pressure of the cooling liquid supplied to the engine so that the liquid may be circulated in the cooling cavities of the engine at velocities that will insure against Stratification of the cooling liquid in places Where circulation is required.

In the drawing: v

Figure 1 is a fragmentary end elevational view of an engine having various parts thereof broken away and shown in cross-section to better illustrate the features of the cooling system employed in the engine.

Figure 2 is a plan view of the engine disclosed by' Figure 1.

Figure 3 is a cross-sectional view taken substantially in the plane of line 33 on Figure 1 and having various parts of the structure broken away and illustrated in crosssection to better illustrate the features of the cooling system embraced in the heads of the engine. a Figure 4 is a diagrammatical illustration of the opera tion of the cooling liquid distribution nozzle disclosed by Figure 5 and showing how the nozzle distributes the cooling liquid throughout the lower part of the inside cavities in each bank of cylinders of the block. I

Figure 5 is a cross-sectional view taken, through the front wall of the engine and illustrating a cooling liquid distribution nozzle employed in the cooling system embracing the invention.

Figure 6 is an end view of one of the distribution nozzles as illustrated by Figures 4 and 5. p

The engine 10 embodying the invention comprising an engine block 11 in which parallel rows of obliquely disposed cylinders 12 are formed. Pistons 13 are adapted to reciprocate in the cylinders 12 in response to the operation of connecting rods 14 which are rotated and reciprocated by the crankshaft 16 of the engine. The cylinders 12 are formed by cylinder walls 17 and are surrounded by cooling cavities 18 which are formed Within the outer or cooling liquid jacket walls 19 of the block 11. The cavities 18 extend between and at the ends of the rows of cylinders 12 and throughout the length of the rows of cylinders 12 and on opposite sides thereof. The cylinders 12 are closed by heads 21 secured to the block 11 by bolts 22. The heads 21 provide firing chambers 23 for each of the cylinders 12 and in Which spark plugs 24 and inlet and exhaust valves 26 and 27 respectively are provided. The firing chambers 23 and v outer end surfaces of each cylinder bank of the block 11. The heads 21 contain coolingliquid cavities 29 which are provided by cooling liquid cavity or jacket walls 31 which enclose a limited 1 amount of space upwardly of the inner walls 28 and adjacent the firing chambers 23. Inlet passages 31 and the exhaust pas k3 sages 32 lead inwardly and outwardly respectively through the cavities 29 and from the inlet valves 26 and the exhaust valve 27. The exhaust passages extend out- :wardly to branch passages 25 leading .to exhaust mani- "folds 33 .and the inlet passages 31 extend inwardly to branch passages 34fleading to one or the other of the main distribution passages 36 of the inlet manifold 37 of the engine 10. It is proposed to construct the walls 38 forming the exhaust passages 32 in such manner as to extend the exhaust passages 32 upwardly and outwardly from the cylinders 12 of the engine with as little curvature as is possiblein the exhaust passages 32. Then it I is proposed to construct the outer side walls 39 of the heads :21 tointersect the outer ends of the passages 32 substantially normally and to extend upwardly from the outer .sides of the heads 21 substantially in parallel relation to the vertical plane of the engine. This will provide exhaustpassages of minimum length which will be adequately cooled adjacent the exhaust valve stem guides 41 and the ports in which the exhaust valves 27 are seated. It is only for the purpose of cooling the exhaust valve stem guides and the exhaust ports that it is necessary to .cool any of the walls in which the exhaust passages 32 are formed. It is considered preferable to provide a separate exhaust passage 32 for each of the exhaust valves 27 of the engine so that the walls 38 may extend directly to the side Walls 39 and therefore be of minimum length.

It is also proposed to form the inner walls 42 of the heads 21.to extend substantially in parallel relation to the axes of the cylinders 12 and to intersect the walls forming the inlet passages 31'substantially normally. It has been the practice heretofore to dispose the walls 42 outwardly toward the inlet manifold 37 and to secure the inlet manifold to the inner walls of the heads. This has been done to increasethe size of the cooling cavities in the heads as may be seen from the fact that the walls of the inlet passages are cooled by the incoming charge and do not require cooling by the cooling liquid of the engine. In the present instance it is proposed to move the inner walls 42 inwardly to enclose within the heads only the space immediately above the cooling cavities 18 on the inside of the cylinders 12 and to reduce to a minimum the cooling liquid cavity 29 within the heads .21. The outer walls 44 of the heads 21 may be disposed substantially in parallel relation to the inner walls 28 and in spaced relation tothe walls forming the outlet passages 31 except 'at the outer edges thereof where they may be turned outwardly slightly in normal relation to the stems for the valves 26 and 27. It will be noted that the walls 39, 42 and 44 of the heads are positioned to include aslittle as possible of the walls forming the inlet and exhaust passages extending through the head toreduce the cavities 29 to a minimum'size.

A pump 46 may be bolted or otherwise secured at 47 to the front of the block 11 for the purpose of supplying cooling liquid, preferably Water, to the cooling cavities 18 and 29 in the block and heads of the engine. Any suitable pump may be employed although in the present instance it is considered preferable to employ a pump with an impeller 48 having vanes 49 which are substantially radially disposed at the outer extremities thereof and curved inwardly at the inner extremities thereof to lead the vanes 49 as .in Figure l the impeller 48 rotates in a clockwise direction. It is customary to drive the impeller 48 by employing a shaft 51 on which the fan of the engine is mounted. This necessitates securing the casing 52 of the pump to the front wall of the engine near the upper part of the block 11. Outwardly of the impeller 48 it is considered preferable to provide an enlarged distribution chamber 53 which completely surrounds the impeller 48 and tapers in opposite directions toward outlet passages 54'leading from the pump casing. The outlet passages 54 at each end of the distribution chamber 53 are adapted to communicate with inlet p ings formed in the front wall 56 of the block 11 near the upper extremities of the cavities 43 that extend the length of the block 11 and inside the cylinders 12. Nozzles 57 are adapted to be pressed in the openings in the walls 56 to extend inwardly of the cavities 43 at one side of the walls 17 of the cylinders 12. Orifices 58 are provided in the rounded outer ends 59 of the nozzles 57. The orifices 58 are not as wide as the nozzles 57 and are elongated in planes between and parallel to the inner surfaces of the inner side walls of the block '11 and the adjacent surfaces of the walls 17 of the cylinders 12. The orifices 58 are also formed in the rounded ends 59 of the nozzles 57 so that the upper extremities of the orifices intersect the side walls of the nozzles toward the extreme ends of the nozzles and beyond the place where the rounding of the ends commence. This results in the ends of the nozzles adjacent the upper ends of the orifices 58 forming curved and downwardly directed deflection means 59 adjacent the extremities of the'nozzles 57. The lower ends of the orifices 58 are adapted to extend beyond the rounded ends 59 and to terminate toward the opposite ends of the nozzles 57. Since the orifices 58 are not as large as the outlet ipassages 54 nor the parts of the nozzles 57 leading to the orifices '58 it will be apparent that the velocity of the cooling liquid flowing through the orifices 58 will be increased by the orifices 58 to discharge the cooling liquid into the upper parts of the inner cooling cavities 43 in high velocity streams as is indicated by the flow lines in Figure 4. The upper parts 59 of the rounded ends of the nozzles will cause these streams to be discharged downwardly in the inner cavities 43 and the narrow and elongated form of the orifices 58 will cause these streams to be directed toward the bottom of the cavities 43 and substantially throughout the greater part of the length thereof. At the lower extremities of the cavities 43 it will be apparent that the cooling liquid in the streams discharged by the nozzles 58 will be deflected between the cylinders 12 and to the lower extremities of the elongated cavities 61 on the outer sides of the cylinders 12. Therefore, the pump 46 will supply cooling liquid to the lower extremities of the cooling cavities 18 in the block '11 and substantially throughout the length of the block 11.

As thecooling liquid in the cavities 18 is displaced upwardly by the continuous supply of cooling liquid through the nozzles 57 the cooling liquid will absorb heat from the cylinder walls 17 for cooling the cylinders and the pistons 13 reciprocating therein. It will also be apparent that the temperature of the cooling liquid will increase as it approaches the upper extremities of the cylinders and that there will be no by-pass through the cooling cavities 18 where the liquid supplied by the pump 46-may take the shortest path of movement between the pump outlets 54 and the upper extremities of the cylinders 12,.

It is proposed to transfer the cooling liquid from the block cavities 18 to the head cavities 29 principally through the pairs-of main supply passages indicated at 62 and 63. The supply passages 62 and 63 may be formed through the lower walls of the heads and the upper walls of the block in parallel relation to the axes of the cylinders 12. It is proposed to locate the passages 62 on theouter sides of the heads 21 and immediately-within the outer side walls 39 which are not disposed in parallel relation to the axes of the cylinders 12 but in substantially parallel relation to the central vertical plane of the engine 10. It is proposed to locate one of the main supply passages .62 between each pair of the cylinders 12. In each pair of the cylinders 12 it is proposed to arrange the inlet valves 26 on the adjacent sides the cylinders and the exhaust valves '27 on the opposite .sides of the cylinders with the valves extending substantially across diameters of thecylinders and substantially aligned throughout the length of each head. It is therefore proposed to arrange the main supply passages 62 adjacent the outer side walls 39 and between pairs of the cylinders 12 in which the inlet valves 26 are disposed on adjacent sides of the cylinders. The supply passages 62 therefore will be located a considerable distance from the exhaust passages 32 which ex tend directly outwardly from the exhaust valves 27. The main supply passages 63 are to be located directly across the heads 21 from the passages 62 and in close proximity to inwardly directed parts 64 of the inner side walls 42 ofv the heads 21. The passages 63 are therefore located between pairs of the cylinders 12 and on the inlet valve sides of the cylinders 12. Immediately above the supply passages 63 are the inlet passages 31 by which combustible mixtures are supplied to the cylinders 12. Since the inlet valves 26 are on adjacent sides of pairs of the cylinders 12 it will be apparent that the inlet passages 31 for each pair of the cylinders 12 may be brought together closely enough so that a common dividing wall may be provided between adjacent passages 31 for the pairs of the cylinders 12. It is proposed to form the, inlet passages 31 of substantially rectangular cross-sectional configuration between the inlet valves 26 and the inner extremities of the heads 21. Under such circumstances the lower walls of each pair of inlet passages 31 will be substantially flat. Since the inlet passages 31 are directed inwardly of the heads 21 and toward the branch passages in the inlet manifold 37 it is possible to position the common lower wall for each pair of the inlet passages 31 in spaced relation to the inner walls 28 of the heads 21 with the inner extremities of the lower walls merging with the inner walls 28 around the seats for the inlet valves 26 and the outer extremities thereof closely approaching the inner walls 28 adjacent the inner side walls 42. Under such circumstances it will be apparent that the common lower walls of the pairs of inlet passages for the pairs of cylinders in each head will provide circulation deflection baflles 66 immediately above each of the main supply passages 63. It will be apparent that when streams of water discharge into the heads 21 through the main supply passages 62 and 63, the streams from the supply passages 62 will move upwardly in the cavities 29 and along the outer side walls 39 of the heads which are disposed obliquely and are directed inwardly with respect to the streams. However, the streams of liquid supplied by the passages 63 will flow inwardly of the cavities 29 and directly against the circulation baflies 66 provided by the lower walls of adjacent pairs of the inlet passages 31. These streams of liquid discharged by the supply passages 62 and 63 will cause a circulation of liquid in the lower part of the cavities 29 in planes extending transversely of the engine heads and substantially throughout the entire length of the engine heads. This will be apparent when it is considered that the streams of liquid discharged by the main supplypassages 63 are prevented from flowing upwardly in the cavities 29 by the bafiies 66, are prevented from flowing outwardly by the inwardly extending parts 64 of the outer side walls 42, are prevented from flowing directly across the cavities 29 by the inlet valves 26 and therefore must divide to form two streams which flow outwardly of the baffles 66 and toward the exhaust valves 27 on opposite sides of each pair of the cylinders 12. It will be noted that each cylinder of the engine has five of the bolts 22 for securing the heads 21 to the block 11. The bolts 22 are arranged in three rows throughout the length of the engine with the middle row of bolts extending through bolt columns 67 and the inner row extending through bolt columns 68. It will be noted that one of the bolt columns 67 is positioned between each pair of the cylinders 12 and immediately adjacent the supply passages 63. These bolt columns will cause the streams of liquid supplied by the passages 63' to divide immediately adjacent the passages 63 to flow around the columns 67 and the places where the lower walls of the pairs of inlet passages 31 merge with the '6 inner walls'28. Also, it'will benoted that a pair of the bolt columns 68' are located on each side of the supply passages 63 and in a position to deflect the divided streams toward the exhaust valves 27. It will therefore be apparent that the divided streams of liquid supplied by the supply passages 63 will flow outwardly from beneath the bafile 66 and toward the ends of the exhaust passages 32 which communicate with the exhaust valves 27 and which extend across the heads 21 in a direction opposite that in which the inlet passages 31 extend. It will be further apparent that the streams of liquid directed upwardly by the supply passages 62 and deflected inwardly by the side walls 39 will entrain liquid in the parts of the cavities 29 between the exhaust passages 32. The liquid so entrained will result in low fluid pressure areas beyond the inner ends of the inlet passages 31 and adjacent the outer ends of the exhaust passages 32. Since low pressure areas Will cause the divided streams of liquid supplied by the passages 63 to flow around the ends of the walls 38 in which the exhaust passages 32 are formed and to cool the walls 38 and particularly the parts of the walls 38 adjacent the exhaust ports formed in the lower walls 28. It will be'noted that the bafflev 66 will direct the divided streams outwardly and immediately adjacent the lower walls 28 and directly toward the exhaust valve seats. After the divided streams of liquid flow around the ends of the exhaust passage walls 38 the liquid will move upwardly along the walls 39 as the liquid is entrained in the stream of liquid discharged by the main supply passages 62.; This movement of liquid around the inlet valves and across the heads adjacent the lower walls 28 and upwardly adjacent the side walls 39 will result in a circulation of liquid trans-. versely of the heads and about an axis extending throughout the length of the heads and normally intersecting the parallel transverse planes through the axes of the cylinders 12. This will be apparent when it is con sidered that at the upper extremity of the walls 39 the liquid will engage the'upper walls 44 and particularly the outer extreme parts of the upper walls 44 which are constructed in such a way as to be normal to the axes of the stems of the valves 26 and 27. These parts of the upper walls 44 will deflect the liquid downwardly and inwardly and toward the upper walls of the pairs of inlet passages 31 and toward the space between and on opposite sides of the pairs of inlet passages 31. The liquid that is directed between and on opposite sides of the pairs of inlet passages 31 will be entrained in the divided streams of liquid flowing outwardly from beneath the inner extremitiesof the baifle 66. V The liquid engaging the upper walls of the pairs of inlet passages 31 will be deflected in opposite directions to be entrained in the liquid moving downwardly between the pairs of inlet passages. It will, therefore, be apparent that instead of the liquid introduced into the heads merely flowing upwardly in the heads and outwardly through the path of least resistance the liquid will be compelled to circulate in the heads and over the walls of the firing chambers 23 and across the parts of the walls in which the exhaust ports are formed, these being the parts of the heads that need the greatest cooling.

It will be noted that the outer side walls 39 merge with the inner walls 28 of the heads at the large ends of the firing chambers 23 which are formed in the inner walls 28 of the heads. The walls 39 also merge with bosses 71 through which pairs of the bolts 22 located on opposite sides of the spark plugs for each cylinder extend. The bosses 71 and the merging Walls 39 and 28 at the larger ends of the firing chambers 23 form relatively thick wall sections 72 which provide relatively low resistance paths for conductivity of heat from the larger ends of the firing chambers 23 and from around the spark plugs 24. The wall sections 72 are surrounded by the cavities 29 in the heads 21 and the cavities 18 in the block 11. These thick wall sections indicated at 72 and thebosses 7-1 therefore willrapidly conductheat to the cavities 29 and 18 andto part'sof the cavities 29 and 18 where relatively wide surfaceareas at'the edges of the sections 72 are exposed to the cooling liquid in the cavities 2'9 and113. In order to increase the conductivity between the sections 72 and the walls of the block 19 so that the heat from the sections 72 may be more'rapidly absorbed by the liquid in the cavities 18 in the block it is proposed to employ metallic head gaskets 73 which will conduct heat better than asbestos or other gaskets which may be employed.

It will be noted that the upper parts of the cavities 29 in the heads 21 are the inner parts of the cavities and that these inner parts are relatively remote from the parts in which liquid is circulated across the exhaust valve ports and the firing chambers of the engines. Cooling liquid therefore may tend to stratify in the upper parts of the cavities 29, particularly above the walls forming the inlet passages 31 and between the upper parts of the side Walls forming the passages 31. The stratifiedcooling liquid in such parts of the cavities 29 therefore is free to move lengthwise of the heads where at the front ends of the heads outlet pasages 74 are formed. Theoutlet passages 74 are adapted to communicate with a passage 76 formed in manifold 77 extending across the heads 21 at the front of the engine. The outlet 78 from the manifold 77 may be connected to the radiator of the engine which by reason of the improved cooling system previously described may be greatly reduced in heat radiating surface and cost. The heads 21 may be made reversible if this is desired and in such instance the outlet passages 74 will be provided at each end of the heads 21. With such passages 74'provided at each end of the heads the passages at the rear of the heads may be closed by walls 76 extending from the connecting wall- 77 in which the inlet and cooling liquid manifolds 37 and 77 respectively may be formed.

At places in the cavities 29 which are somewhat remote from the main supply passages 62 and 63 it may befound desirable to provide secondary supply passages indicated at 75. These may be employed to supply additional cooling liquid from the cavities in the block to the cavities in the head and to prevent Stratification of liquid in the remote parts of the cavities of. the heads. Also, one of these auxiliary passages which is indicated at 80 may be positioned about the middle of the cavities 29 and adjacent the exhaust cross-over passage 79. The passage 79 leads from one of the exhaust passages 32 toward the middle of the engine and communicates-with the exhaust heat passage 81 which is formed in the con necting wall 77 and which is employed for heating the inlet manifold 37.

We claim:

1. A cooling system for an internal combustion engine 8 comprising, an engine block having a row of cylinders formed therein and haVin'gcoolihg cavities formed around said cylinders and on'opposite sides of said cylinders and extending throughout the-length of said block, a cooling liquid circulating pump secured to one end of said block and having an outlet disposed in opposed relation-toone of said cavities on one side of said cylinders and communicating with said oneof" said cavities adjacent the outer extremity of the adjacent oneof said cylinders,'a nozzle extending from said outlet into said one of' said cavities and having an orifice formed at the inner end thereof, said orifice being formed in said nozzleto discharge-cooling liquid in a fiat jet directed toward thelower extremity of said one of said cavities and throughout the iength of'said one of said cavities and along said one side of said cylinders, and means exhaustingsaid cooling liquid ]supplied to' said cavities through the upper wall of said lock. 1

2. A cooling system for an internal combustion engine as defined by claim 1 and in which said row of cylinders is obliquely disposed and one cavity is higher than the other of the two cavities which extend throughout the length of said block and are disposed on opposite" sidesof said row of cylinders.

3. A cooling system for an internal combustion enginecomprising an engine block having a row of cylinders formed therein and cooling cavities on opposite sides of and between and at the'ends of said cylinders and throughout the length of said block, an inlet passage formed in an end wall of said block and'in opposed relationito the upper extremity of oneof said cooling cavities and'on'one side of said row of cylinders, an inlet nozzle extending into said one of said cavities from said inletpassage and normally to the transverse planes of the axes of said cylinders, saidinlet nozzle being'formed at the inner extremity thereof to provide a rounded end, a' slot formed in said rounded end of said nozzle and providing a discharge orifice in said nozzle, said slot being an elongatedslot and being narrower than said rounded end of said nozzle and being adapted to extend from below the upper. extremity of said rounded end to beyond the lower extremity ofsaid rounded end, said orifice being adapted to discharge cooling liquid into said one of said cavities andfrom said inlet passage and by forming a relatively fiat and diverging and downwardly projecting. jet of cooling liquid. directed toward and along the lower extremity of saidfone of said cavities, and means for exhausting said cooling liquid from said cavities and through an upper wall of said block.

Muir July 5, 1927 Montabone May-20; 1952 

